Recent user interface technology is related to an electrical-electronic processing technique for sensing/predicting/interpreting a behavior or intention of a user. In other words, the user interface technology may be said to detect all minor actions of the user, guess an intention inherent in the action of the user, and realize an electrical-electronic processing method corresponding to the intention to assist the user to manipulate a device more easily. A touch screen of a smartphone may be said to be a representative example of the recent user interface. For example, when the user contacts the touch screen with two fingers and then increases a distance between the two fingers, a processor of the smartphone may determine that a user intends to enlarge an image output through the touch screen. Also, the processor may perform an image processing, namely, enlargement corresponding to movements of the two fingers. Such user interface technology may be said to core technology for achieving an increase in user convenience and advancement of automation technology.
The user interface technology may be applied to all industrial fields and accordingly, may also be applied an industrial area related to producing/appreciating/sharing of content. In a view of a typical user, a user interface related to content appreciation may be usefully utilized. At this point, in a view of the user interface, whether the user currently appreciates acoustic content may be handled as important context information.
Until now, there is not an effective technique capable of easily determining whether the user is appreciating the acoustic content. In particular, since a solution capable of checking whether the user is appreciating the acoustic content only with a signal processing technique has not been suggested, a research about this is necessary.